Department of Anthropology, University of California, Davis
Saturday 9:30-9:45, Grand Ballroom II
Studies interpreting antemortem tooth loss (AMTL) in the human fossil record as evidence of more human-like behaviors or biology assume that modern humans have a higher frequency of AMTL than non-human primates. The single test of this assumption presented supporting preliminary data, but did not consider potentially confounding demographic variables such as age.
This study explores the effects of age and sex on AMTL in a skeletal sample of 486 human hunter-gatherers, Pan troglodytes, Papio sp., and Pongo pygmaeus. A binomial regression model with genus, age, and sex as main effects and an interaction effect between genus and age indicates that AMTL is less frequent in all three non-human primate groups than in humans even when accounting for age and sex. Age is an important predictor of AMTL, with each decade increasing the odds of AMTL by a factor of 3.0 (95 % CI: 2.3-4.0), but there is little to no evidence in the sample for sex or genus specific age effects on AMTL. The lack of support for genus specific age effects implies that differences in the pace of aging among genera are not significantly impacting AMTL.
These results corroborate the assumption that modern humans have a higher frequency of AMTL than do non-human primates and provide support for hypotheses that link AMTL to modern human behaviors or biology. The importance of age suggests that the high frequency of AMTL in modern humans may be explained in part by our increased longevity.
This study was funded with generous support from the Leakey Foundation, University of California, Davis, Department of Anthropology, and the UC Davis Institute of Governmental Affairs.